A large number of antennae are conventionally built into aircraft, for example, airplanes or helicopters. These antennae are arranged at various points on the aircraft fuselage or on the airfoils and thereby perform a wide variety of functions.
A first application of antennae in aircraft involves data communication. In this case, corresponding antennae make it possible to exchange speech, images or other user data between the aircraft and (a) another aircraft, (b) a satellite communication system, or (c) a base station, for example a tower, a gate or an airport terminal. Data is communicated in frequency ranges of a few MHz up to a few thousand MHz.
A second application of antennae in aircraft involves position determination. Corresponding antennae make it possible to determine, for example, the height above ground level (e.g., radar altimeter (RALT)) or the absolute position above sea level (e.g., Global Positioning System (GPS)). Other applications based on relative position determination include instrument landing systems (e.g., instrument landing system (ILS)) or collision warning and avoidance systems (e.g., traffic collision avoidance system (TCAS)). Depending on the application, frequency bands of up to several GHz are used.
Other applications of antennae in aircraft include, for example, weather radars (e.g., WXR) or other systems which increase air safety. Depending on the application scenario, individual monopole or dipole antennae, or what are known as antenna arrays can be used. In order to improve the failsafe performance of the corresponding systems, redundant communication systems comprising antennae which are correspondingly redundant are provided in the majority of aircraft.
Integrating additional antenna units in aircraft is time-consuming, expensive and limited by factors such as weight, size and power consumption. Therefore, if possible, retrofitting additional antenna units should be avoided.
There is a need to provide an aircraft which comprises a plurality of antenna units and allows data communication with a base station (e.g., a tower, a gate or an airport terminal) at a relatively fast transmission speed.